Recently, Bluetooth (registered trademark) attracts attention as wireless communication means for short range, and various kinds of compliant equipment have been developed and marketed.
The wireless communication system using radio waves, typified by the Bluetooth has-advantages such as having no directivity and having higher transparency in comparison with a conventional infrared data communication system including IrDA. It was necessary to make devices communicating with each other face adequately when using communication with strong directivity, such as IrDA. However, in the communication system including the Bluetooth, such limitation in positioning is not required.
The Bluetooth specification is under control of Bluetooth SIG, Inc., and details of the specification are available from Bluetooth SIG, Inc. For example, in the communication utilizing Bluetooth, a device called “master” for controlling the communication performs broadcast transmission of a device detection message for detecting devices existing around it.
And the master can detect the devices existing around it, that is, communicable devices, by means of a response message transmitted from a device (slave) which received the device detection message.
In addition, when establishing communication between the master and a specific one of the detected devices, the master specifies the one on the basis of identification information of each device contained in the response message and establishes the communication.
In the Bluetooth system, information called “Bluetooth address” is assigned to respective devices as information for identifying individual devices. The Bluetooth address is uniquely given to each device, the information is used for various processing including device control and the like.
It is to be noted that in the Bluetooth system, a network comprising a master and slaves is called a “piconet”. A single piconet can have one master and seven slaves belonging thereto, at maximum. All the devices belonging to a single piconet are in a condition that a frequency axis (frequency hopping pattern) and a time axis (time slot) thereof are in synchronization.
Furthermore, a network in which a plurality of piconets are connected can also be configured, and this is called a “scatternet”.
In addition, in the Bluetooth system, specifications referred to as “profile” which specifies data transmitted/received in wireless communication and communication steps thereof with regard to each service is established. In accordance with the profile, services available through respective devices are represented.
For example, in a PAN (Personal Area Network) profile being developed as one of the profiles, a communication method between slaves in a piconet is defined. Devices belonging to a piconet constituted in accordance with the PAN profile are allowed to transmit/receive various data through the piconet as a single network. Similarly, in a scatternet, it will be defined that various data are transmitted/received in the scatternet as a single network. This network may be a network based on an IP (Internet Protocol), for example.
And at the time of configuring such a network, details such as, which device should be a master, which device should be a slave, or through which service the communication should be carried out, are determined by the master which acquires information regarding the peripheral devices using the device detection message as described above, in accordance with an instruction from a user, for example.
However, in wireless communication using Bluetooth, a device detection message is broadcasted to all devices existing in a search range (an area having a radius of 10 meters to 100 meters, for example). Therefore, a user should check information displayed on a screen and should select, from the devices transmitting a response message to the device detection message, a device to communicate with. This is a problem of spending time as a result.
In other words, such a device selecting operation is required every time the communication is carried out, which is extremely inconvenient to the user. This problem will possibly get worse as the Bluetooth-compliant devices become popular in the future.
In addition, when actually transmitting/receiving data, the user is required to select a desired service among services notified by a target device. This also spends much time until the communication starts.
Furthermore, even after selecting the device to communicate with and the service applied between the devices, the user may require inputting a number in a predetermined digit, that is, a pass key, which is common to both the communicating devices. This input operation of the passkey is an operation needed at an initial connection between devices, especially which require ensuring of security, and this is inconvenient for carrying out communication.
Therefore, there has been a problem that, due to various factors described above, it is not easy for the user to make configuration of a communication group (network) comprising a plurality of devices based on the Bluetooth system.